paterson solution

// code for producer (j) 
  // producer j is ready 
// to produce an item 
flag[j] = true;  
// but consumer (i) can consume an item 
turn = i;  
// if consumer is ready to consume an item 
// and if its consumer's turn 
while (flag[i] == true && turn == i) 
    { // then producer will wait } 
    // otherwise producer will produce 
    // an item and put it into buffer (critical Section) 
    // Now, producer is out of critical section 
    flag[j] = false; 
    // end of code for producer 
    //-------------------------------------------------------- 
    // code for consumer i 
  
    // consumer i is ready 
    // to consume an item 
    flag[i] = true; 
  
    // but producer (j) can produce an item 
    turn = j; 
  
    // if producer is ready to produce an item 
    // and if its producer's turn 
    while (flag[j] == true && turn == j) 
  
        { // then consumer will wait } 
  
        // otherwise consumer will consume 
        // an item from buffer (critical Section) 
  
        // Now, consumer is out of critical section 
        flag[i] = false; 
// end of code for consumer